The biological effects of 60 hertz electric fields will be studied to provide a basis upon which to assess the risk of exposure to such fields in the environment. The following will be determined: 1. The effect on mice of chronic exposure to 0.5 kv/m; 2. The effect on healing in rats on 1/5 kn/m; and 3. The effect on various physiological parameters of rats of 1-30 days exposure to 3/5 kv/m. Other related studies will also be performed.